The long-term scientific goal of this research is to elucidate the neurophysiological basis of decision-making using as a model coding of behaviorally significant social odors in the mouse olfactory system. Behavioral choices depend on analyzing sensory information, integrating that information with knowledge from past experience, and responding appropriately to the specific circumstances. A mouse perceives sufficient sensory information to respond effectively to another mouse simply by smelling its individual odor, because these multi-faceted odors provide simultaneous information about the sex, age, origin, health, diet, social/reproductive status, and specific identity of the donor. Enough is now known about the subtle distinctions mice make between the distinctive features in odors and about coding of single odorants in the mouse olfactory system to integrate this knowledge and tackle coding of biologically relevant odors. With powerful neuroanatomical and mouse genetics techniques and a deep understanding of the subtleties of mouse behavior, we will determine how the distinctive features of complex social odors are coded in the mouse olfactory system, emphasizing odor quality representation and neural network processing in the main and accessory olfactory bulbs (OB). We hypothesize that the anatomy of the olfactory bulbs evolved to facilitate this important process of odor analysis and synthesis. We will use c-fos expression to map the patterns of activation of glomeruli in the olfactory bulbs of male mice after smelling urine from female donors that vary in their genetic identity, odorous dietary metabolites, and estrous state. Differences across groups will reveal specific patterns that are associated with these particular odor features and provide insights into how differential glomerular activation facilitates analysis of odors into distinct features. We will construct these odor maps in transgenic mice in which olfactory sensory neurons (OSN) expressing the M5 family of transient receptor potential channels have been genetically labeled to determine whether this particular OSN subfamily contributes to the process of odor feature analysis. Although these experiments may not appear to be directly connected with decision making, they represent the first step in understanding the relationship between odor perception and the odor preferences that constitute the behavioral choice, which is basic to the decision-making process. Determining how odor analysis leads to effective choices and then ascertaining what short-circuits this process, leading to maladaptive choices, in mice should provide insight into how human behavioral choices can either succeed or go awry, as occurs in a broad range of human psychopathologies. [unreadable] [unreadable] [unreadable]